Tissues Flashcards
1
Q
Epithelial tissue
A
- Covers surfaces
- Cells connected
- Separates compartments
- Cells define function
- Diversity of secondary functions
- Forms glands
2
Q
Connective Tissue
A
- Connects!
- Extracellular matrix + fluid defines structure and function
- Liquid to solid matrix
eg- blood, bone adipose
3
Q
Muscle tissue
A
- Contractile
- Long thin cells
- Cytoplasm of cells packed with contractile apparatus
- Shorten lengths, close down spaces
- Skeletal, smooth, cardiac muscle
4
Q
Striated
A
highly ordered arrangement of contractile proteins.
5
Q
cardiac muscle
A
Is kind of a hybrid of both smooth and skeletal muscle.
contains:
- striations
- nucleus is more round and in the middle
- interclated disc
6
Q
skeletal muscle
A
contains:
- striations
- nucleus is on top (periphery)
7
Q
smooth muscle
A
doesn’t have striations
has nucleus in the middle
8
Q
Non-Striated
A
less ordered arrangement of contractile proteins
9
Q
Nervous tissue
A
- Communication
- Neurons + support cells
- Receives, generates and transmits electrical signals
- Integrates information
eg - spinal cord, cerebellum
10
Q
Neurone: Basic component of nervous tissue
A
Neuronal function
- similar in all animals
Plasma membrane electrical signals
- generation (nerve impulses/action potentials)
- conduction to farthest points of cell.
Neurons - 4 regions
- cell body (soma),
- dendrites,
- axon,
- terminals.
11
Q
Epithelial tissue
A
Covers surfaces
Separates compartments
epithelium and endothelium
12
Q
How does epithelial tissue maintain coverage of surfaces?
A
No contact inhibition
Cell - cell junctions
Cell - ECM junctions
13
Q
Cell – cell junctions
A
- Desmosomes
- Tight junctions
- Gap junctions
14
Q
Desmosomes (adhering junctions; macula adherens)
A
looks like “]|[”
Function = firm anchorage
in absorptive endothelium
15
Q
Tight junctions (occluding junctions)
A
looks like “X”
Function = seals intercellular spaces
in intestine endothelium
16
Q
Gap junctions (communicating junctions; nexus)
A
looks like “X” or “O” with many “daisies” inside
Function = cell to cell communication
in cardiac muscle - interclated discs
17
Q
Desmosomes, Tight junctions
A
Maintain integrity of epithelial layer (surface covering)
18
Q
Basement membrane contains
A
BL = Basal Lamina RL = Reticular Lamina
19
Q
Epithelium – secondary roles
A
Thick – wear and tear
Thin - diffusion
20
Q
Epithelium – secondary roles
Movement - Cilia
A
Cilium:
- Finger like projection from apical surface (in trachea)
- Tubulin doublet
21
Q
Epithelium – secondary roles
Absorption - Microvilli
A
Microvillous:
- Finger like projection from apical surface (microvilli, villus)
- Actin cytoskeleton + spectrin cross-links
22
Q
Epithelial tissue
A
- Covers surfaces; separates compartments
- Very varied
- Function(s) depends on cells and their specialisations rather than extracellular matrix
- Good adaptive powers
- Good regenerative powers, eg after skin cut
23
Q
Classification of epithelia
A
Simple epithelia
- sqamous (stretched out or round)
- cuboidal (squarish)
- columnar (like columns)
Stratified epithelia
- sqamous (stretched out or round)
- cuboidal (squarish)
- columnar (like columns)
- transitional (alien face to round - in urinary bladdar)
- pseudostratified columnar epithelium (found in trachea)
24
Q
Glands
A
- Collections of secretory epithelial cells (mostly)
- Single celled or multicellular
- Exocrine (secrete into tubes)
- Endocrine (secrete into blood)
25
Exocrine glands
simple (eg- sweat gland)
- tubular
- acinar (grape shaped)
compound (eg- slivary gland)
- tubuloacniar
26
Exocrine glands
Mucous glands
- Secretion rich in proteoglycans
- Secretion + water gives mucus (protects tissues from harm)
Eg. Mucous glands of trachea , gut
Serous glands
- Protein rich secretion
Eg. Exocrine pancreas
27
Exocrine glands:Production of secretion
Exocrine pancreas
28
Myoepithelial cells
Myo = muscle
Thin outer cell is myoepithelial cell and these cells contract and squeeze out the mucus or whatever is hard to get out out
Myoepithellial cell surround the pore
29
Endocrine glands:Proteinaceous secretion
Insulin and glucagon are secreted out.
Production is taking place at the base and this time the secretion is through the blood, the secretion is taken out the top and goes straight into solution.
Steroid hormones can't be stored as they are lipid soluble and they can leak out so don’t stick on the receptor outside. This means they pass straight through the membrane.
30
Endocrine glands:Steroid gland
eg. Adrenal cortex
| Lots of mitochondria are found as lots of these are needed to make steroids on demand
31
Epithelial components of liver
Parenchyma – Hepatocytes (epithelial cells)
- Hepatocytes arranged in rows (or cords) between blood vessels
- Multiple functions, including secretion
Support epithelial cells:
- line blood vessels
- line bile ducts
32
Hepato
to do with liver
33
Cytes to do wit cells
to do with cells
34
Sinusoids
a small irregularly shaped blood vessel found in certain organs, especially the liver
35
Epithelial components of kidney - 1
the kidney looks like an airpod.
- the bottom long bit is the ureter
- as it turns into the inner curve (white) that is the pelvis
- the outer curve (pink) is the cortex
- the little bulbs between the outer and inner curve is medulla
36
Kidneys get rid of
everything but take back what it needs.
| Urine test is a sign of how healthy you are as if it fails then you leak out things you need into your urine
37
Epithelial components of kidney - 2
Parenchyma – Epithelial cells
- Epithelial cells organised into nephrons
- Multiple functions, including filtration of blood, partial absorption of filtrate, overall to release urine from kidney
Support epithelial cells:
- line blood vessels
- line renal pelvis (which receives toxic urine)
38
Resistant epithelium is not affected
by toxins as urine can then sit around for a few hours before it is disposed of.
39
Abnormal function of epithelial cells
- over-proliferation
- under-proliferation
- over-secretion
- under-secretion
- loss of cilia / ciliary beat
40
Abnormal function of glands - Pituitary
Growth hormone
- Over production – pituitary giantism
- Under production – pituitary dwarfism
41
Abnormal function of glands - Uterine tube
```
Mucous glands (single cell glands)
- Chlamydia trachomatis (STD) makes thick mucus which causes ovum/sperm to become trapped – infertility
```
42
Connective Tissue
```
Blood / bone marrow
Mucous
Reticular
Loose
Dense - regular
Dense - irregular
Cartilage
Bone
Adipose (fat)
```
43
Connective tissue - ECM
Fibres – ‘rope-like’
Ground substance – ‘jelly-like’
Tissue fluid - liquid
44
Fibres in ECM
Collagen (tendon)
- (reticulin - lymph)
Elastin (Aorta)
bag of tangerine is reticular
45
Collagen
```
30% body weight
Inelastic but flexible
Great tensile strength
19+ types
Type I in tendons
Type III is reticulin
Type IV in basal lamina (non-fibrous)
```
made from fibroblast and forms triple stranded helix.
46
Reticulin (Type III collagen)
Network, groups of cells trapped by the (46)
| When lymph is flowing through they can catch what they need in the reticulin (tangerine net like structure) they have.
47
Elastic fibres
Protein elastin
Stretch 1.5 times resting length and return to original shape
Microfibrils and amorphous component
Generally found in sheets rather than fibres
Yellow in colour (aorta)
48
Connective tissue - ECM - Ground substance
semi-solid gel
- Proteoglycans (protein core + glycosaminoglycans)
- Hyaluronic acid
- Glycoproteins (laminin, fibronectin, +)
49
Connective Tissue can be
```
Loose
Dense regular (tendon)
Dense irregular (sebaceous gland on skin)
```
50
Loose connective tissue
Permanent (fixed) cells
- Fibroblasts
- Macrophages
- Adipocytes
- Mast cells
- Undifferentiated mesenchyme cells
Transient cells
- White blood cells
51
Abnormal function of Connective Tissue
- Blood / bone marrow - leukaemia
- Loose / dense - loss/abnormal fibres (epidermolysis bullosa)
- Cartilage - tear
- Bone – osteoporosis/petrosis
